Aspects Of Instrumentation Research Articles

Brief Introduction to Neutron Scattering and Global Neutron User Facilities

Neutrons play a vital role as a powerful tool in basic science and applied research. In this article, the basic properties of neutrons, their generation and detection, as well as some fundamental aspects of neutron instrumentation are introduced. Neutron user facilities, at which the user may obtain more specific information and apply for beam time, are also discussed.

Early Modern Mathematical Instruments

In considering the appropriate use of the terms "science" and "scientific instrument," tracing the history of "mathematical instruments" in the early modern period is offered as an illuminating alternative to the historian's natural instinct to follow the guiding lights of originality and innovation, even if the trail transgresses contemporary boundaries. The mathematical instrument was a well-defined category, shared across the academic, artisanal, and commercial aspects of instrumentation, and its narrative from the sixteenth to the eighteenth century was largely independent from other classes of device, in a period when a "scientific" instrument was unheard of.

Advances in top-down proteomics for disease biomarker discovery

Top-down mass spectrometry strategies allow identification and characterization of proteins and protein networks by direct fragmentation. These analytical processes involve a panel of fragmentation mechanisms, some of which preserve protein post-translational modifications. Thus top-down is of special interest in clinical biochemistry to probe modified proteins as potential disease biomarkers. This review describes separating methods, mass spectrometry instrumentation, bioinformatics, and theoretical aspects of fragmentation mechanisms used for top-down analysis. The biological interest of this strategy is extensively reported regarding the characterization of post-translational modifications in biochemical pathways and the discovery of biomarkers. One has to bear in mind that quantitative aspects that are beyond the focus of this review are also of critical important for biomarker discovery. The constant evolution of technologies makes top-down strategies crucial players in clinical and basic proteomics.

Ten years of cryomagnetic W7-X test facility construction and operation

The construction, commissioning, and operation phases of the W7-X cryomagnetic test facility in CEA Saclay lasted ten years. The large diversity of equipments called, specialties involved and problems solved attest the expertise that was required to operate the test facility and test the coils. Nearly one hundred cryogenic tests were performed on the seventy W7-X coils, at a rate always increasing, using two cryostats each holding two coils. This paper presents the test facility and its operation first, the cryogenic difficulties that were confronted with their solutions, the electro-magnetic difficulties encountered along with corrective actions, and finally the instrumentation and data acquisition aspects.

Evanescent wave cavity-based spectroscopic techniques as probes of interfacial processes

Evanescent wave cavity ring-down spectroscopy (EW-CRDS) is a surface sensitive technique, which allows optical absorption measurements at interfaces with good time resolution. In EW-CRDS, a pulsed or modulated laser beam is coupled into an optical cavity which consists of at least one optical element, such as a silica prism, at the surface of which the beam undergoes total internal reflection (TIR). At the position of TIR, an evanescent field is established whose amplitude decays exponentially with distance from the boundary. This evanescent field can be exploited to investigate interfacial properties and processes such as adsorption and surface reactions, with most applications hitherto focusing on solid/liquid and solid/air interfaces. As highlighted herein, EW-CRDS is particularly powerful for investigations of interfacial processes when combined with other techniques such as basic electrochemical measurements and microfluidic or hydrodynamic techniques. In this tutorial review, the basic elements of EW-CRDS will be introduced and the relative merits of different configurations for EW-CRDS discussed, along with various aspects of instrumentation and design. The type of information which may be obtained using EW-CRDS is illustrated with a focus on recent examples such as molecular adsorption/desorption, deposition/dissolution of nanostructures and interfacial redox reactions. The comparatively new, but complementary, cavity technique of EW-broadband cavity enhanced absorption spectroscopy (EW-BB-CEAS) is also introduced and its advantages compared with EW-CRDS are discussed. Finally, future developments and trends in EW-cavity based spectroscopy are predicted. Notably, the potential for extending the technique to probe other interfaces is exemplified with a discussion of initial interfacial absorbance measurements at a water-air interface.

The Development and Commercialisation Aspects of a Practical Feed Intake Measurement Instrumentation to be Used in Livestock Buildings

The aim of the research presented in this paper was to further develop and field-test a simple and robust feed-mass measurement apparatus in order to facilitate the on farm feed-intake measurement of a distinct group of livestock. The underlining technology described in this article is known as a “mass-flow” measurement technology. After progressing through a number of development stages, the final version of the feed measurement apparatus was developed in close collaboration with an industrial partner. The measurement apparatus underwent significant and continuous changes during the study. The hardware and software were progressively improved on by the utilisation of magnetic coupling technology, the development of a calibration function, the integration of a control system and user interface. These improvements were the results of assessment of the instrument and the recursive identification of opportunities for enhancements. Experiments conducted under controlled conditions proved that the reliability and precision of the apparatus was excellent under simulated field conditions and was not affected by change in feed temperature and/or feed composition. A limited number of tests were also conducted on a commercial pig farm with encouraging results. Future development of the feed-measurement unit has the potential to improve the technology to a level where actual feed wastage can be measured and reduced by innovative use of the underlying technology.

Capillary Microfluidic Sensor for Determining the Most Fertile Period in Cows

This paper presents a new method of optoelectronic determination of cow fertility, based on a microfluidic fiber-optic capillary sensor. The current state of the art of fiber-optic capillary sensors is discussed briefly along with aspects of instrumentation and applications. Unlike classical fiber-optic sensors which are based on changes in light propagation inside the fiber in response to external conditions, optical capillary sensors rely on changes of light transmission within capillaries filled with the liquid to be analyzed. This approach opens up interesting new possibilities for the application of capillary microfluidic sensors, while raising specific issues relating to their construction, materials and technology. The investigated sensor uses light switching forced by local heating in a capillary filled with bovine vaginal fluid. The dynamically recorded data were processed in an artificial neural network. We were able to observe changes in the cow’s fertility cycle allowing us to identify when an individual cow was in the middle part of standing estrus which is most situated for insemination.

Recent development in PET instrumentation.

Positron emission tomography (PET) is used in the clinic and in vivo small animal research to study molecular processes associated with diseases such as cancer, heart disease, and neurological disorders, and to guide the discovery and development of new treatments. This paper reviews current challenges of advancing PET technology and some of newly developed PET detectors and systems. The paper focuses on four aspects of PET instrumentation: high photon detection sensitivity; improved spatial resolution; depth-of-interaction (DOI) resolution and time-of-flight (TOF). Improved system geometry, novel non-scintillator based detectors, and tapered scintillation crystal arrays are able to enhance the photon detection sensitivity of a PET system. Several challenges for achieving high resolution with standard scintillator-based PET detectors are discussed. Novel detectors with 3-D positioning capability have great potential to be deployed in PET for achieving spatial resolution better than 1 mm, such as cadmium-zinc-telluride (CZT) and position-sensitive avalanche photodiodes (PSAPDs). DOI capability enables a PET system to mitigate parallax error and achieve uniform spatial resolution across the field-of-view (FOV). Six common DOI designs, as well as advantages and limitations of each design, are discussed. The availability of fast scintillation crystals such as LaBr(3), and the silicon photomultiplier (SiPM) greatly advances TOF-PET development. Recent instrumentation and initial results of clinical trials are briefly presented. If successful, these technology advances, together with new probe molecules, will substantially enhance the molecular sensitivity of PET and thus increase its role in preclinical and clinical research as well as evaluating and managing disease in the clinic.

‘Operational health’ monitoring for confidence in long term electric field measurements

The paper describes practical aspects of electrostatic fieldmeter instrumentation for long term monitoring of electric fields in adverse environmental conditions. Examples of applications have been in studies of tank washing on large crude oil tankers and measurement of atmospheric electric fields. Particular attention is drawn to the technique developed for continuous monitoring of operational health to justify confidence in observations.

Electromagnetic Induction in the Earth

Electromagnetic methods are of particular importance in geophysics as they provide a unique view of the Earth’s interior through imaging its geoelectrical structures. The electrical conductivity of the Earth is sensitive to fluid content, ore minerals, lithological changes and temperature, which allow a wide range of applications. These include monitoring environmental problems, exploring natural resources, searching for potential natural hazards and studying the interior structure of the Earth and other planets. In this field of the Earth Sciences, research in electromagnetic methods is continuously advancing, improving the instrumentation and methodological aspects, leading to substantial results in their applications, and finding solutions to the challenges presented.

Enhanced Oil Recovery Pilot Testing Best Practices

Summary Enhanced-oil-recovery (EOR) implementation is complex, and successful applications need to be tailored to each specific reservoir. Therefore, a systematic staged evaluation and development process is required to screen, evaluate, pilot test, and apply EOR processes for particular applications. Pilot testing can play a key role in this process. Before field testing, pilot objectives need to be clearly defined and well spacing, pattern configuration, and injectant volumes determined. This paper outlines a staged approach to EOR evaluation and focuses specifically on pilot testing best practices. These best practices were derived from ExxonMobil's extensive piloting experience, which includes more than 50 field pilot tests covering the full range of EOR processes. Topics covered include: (1) determining whether a pilot is needed and defining pilot objectives, (2) considerations for successful pilot design, (3) types of pilots and their advantages and disadvantages, (4) tools and techniques for assessment of key reservoir mechanisms, and (5) minimizing uncertainty in pilot interpretation. Key issues that are often addressed by pilots are discussed, including areal sweep and conformance, gravity override, viscous fingering, and loss of mobility control. Also included are aspects of instrumentation and measurements in pilot injection, production, and monitoring wells. Several ExxonMobil piloting examples are used to illustrate the best practices, including a single-well injectivity test, an unconfined pilot with observation wells, a small-scale confined pilot, and a large-scale multipattern pilot.

Instrumentation and Fusion for Congenital Spine Deformities

A retrospective clinical review. To review the use of modern instrumentation of the spine for congenital spinal deformities. Spinal instrumentation has evolved since the advent of the Harrington rod. There is a paucity of literature, which discusses the use of modern spinal instrumentation in congenital spine deformity cases. This review focuses on modern instrumentation techniques for congenital scoliosis and kyphosis. A systematic review was performed of the literature to discuss spinal implant use for congenital deformities. Spinal instrumentation may be safely and effectively used in cases of congenital spinal deformity. Spinal surgeons taking care of children with congenital spine deformities need to be trained in all aspects of modern spinal instrumentation.

System identification of soil behavior from vertical seismic arrays

A down hole vertical seismic array is a sequence of instruments installed at various depths in the earth to record the ground motion at multiple points during an earthquake. Numerous studies demonstrate the unique utility of vertical seismic arrays for studying in situ site response and soil behavior. Examples are given of analyses made at two sites to show the value of data from vertical seismic arrays. The sites examined are the Lotung, Taiwan SMART1 array and a new site installed at Jingliao, Taiwan. Details of the installation of the Jingliao array are given. ARX models are theoretically the correct process models for vertical wave propagation in the layered earth, and are used to linearly map deeper sensor input signals to shallower sensor output signals. An example of Event 16 at the Lotung array is given. This same data, when examined in detail with a Bayesian inference model, can also be explained by nonlinear filters yielding commonly accepted soil degradation curves. Results from applying an ARMAX model to data from the Jingliao vertical seismic array are presented. Estimates of inter-transducer soil increment resonant frequency, shear modulus, and damping ratio are presented. The shear modulus varied from 50 to 150 MPa, and damping ratio between 8% and 15%. A new hardware monitoring system - TerraScope - is an affordable 4-D down-hole seismic monitoring system based on independent, microprocessor-controlled sensor Pods. The Pods are nominally 50 mm in diameter, and about 120 mm long. An internal 16-bit micro-controller oversees all aspects of instrumentation, eight programmable gain amplifiers, and local signal storage.

Quasi-Confocal Frequency Domain Imaging for Improved Depth Perception and Selective Suppression of Fluorescent Emissions

This paper describes an integrated dual modality quasi-confocal frequency domain imaging system in the focal volume. A detailed theoretical analysis of the signal to noise ratio in confocal volume imaging is performed followed by experimental analysis. The instrumentation aspects of the system are also described in detail. The proposed system and methodology found to improve the depth perception and effective in obtaining selective suppression of fluorescence emissions. Investigations and related experimental analysis for conventional and a probe based system were carried out and presented in this paper.

Multicenter Comparison of Different Real-Time PCR Assays for Quantitative Detection of Epstein-Barr Virus

Quantification of Epstein-Barr virus (EBV) in peripheral blood is important for the diagnosis and management of serious EBV diseases, including posttransplant lymphoproliferative disorder. A variety of PCR-based methods are currently in use; however, there is little information on their comparability. This study assessed the relative performance of different quantitative assays. A multicenter comparative study was performed at eight sites using three panels consisting of serial dilutions of quantified EBV DNA and extracts from a total of 19 whole-blood specimens. Samples were distributed and tested blindly. Instrumentation, probe chemistries, amplification targets, and other test-related aspects varied considerably between laboratories. Each laboratory's calibration curve indicated strong evidence of a consistent log-linear relationship between viral load and cycle threshold, suggesting that intralaboratory tracking of a given patient would yield similar relative quantitative trends among the participating test sites. There was strong concordance among laboratories with respect to qualitative test results; however, marked quantitative discordance was seen. For most samples, the across-laboratory interquartile range of the reported viral load (in copies/microl) was roughly 0.6 log-units, and for one sample the overall range was approximately 4.2 log-units. While intralaboratory tracking of patients may yield similar results, these data indicate a need for caution when attempting to compare clinical results obtained at different institutions and suggest the potential value to be gained by more standardized testing methodology.

Development of a capillary electrophoresis system coupled to sequential injection analysis and evaluation by the analysis of nitrophenols

A combination of a laboratory-made capillary electrophoresis system and a sequential injection analysis equipment is described. For characterization, the system was successfully applied to the separation and quantification of nitrophenols. A blue LED was used as light source, and hydrodynamic injection was carried out by using a pressure-stable solenoid valve and an inflatable pressure reservoir. A good reproducibility of migration time (0.5%) and peak heights (5%) were obtained. The calibration by using peak heights was found to be linear up to 776 µmol L−1 for all three compounds. The system was robust and reliable for autonomous analysis without observation. All maintenance requirements including the conditioning of the capillary and flushing of both buffer reservoirs were carried out automatically. Instrumentation aspects of the capillary electrophoresis part are compared with former described hyphenated flow systems showing maximal operation versatility. Instrumental control and data evaluation were carried out using the software package AutoAnalysis.

Environmental applications of liquid-waveguide-capillary cells coupled with spectroscopic detection

Long path-length liquid-waveguide-capillary cells (LWCCs) comprise a capillary with a refractive index (RI) lower than the RI of the liquid core. This enables light introduced into the capillary core to be totally internally reflected down the capillary towards the detector, resulting in an enhancement of sensitivity and improved limits of detection compared with conventional spectroscopic techniques. LWCCs are also versatile and have been used in combination with spectrophotometry, Raman spectroscopy and luminescence detection for quantification of a range of chemical species at nanomolar concentrations. This article describes the properties and the practical aspects of LWCC instrumentation and applications to environmental matrices. We also present summary tables of applications, including figures of merit, LWCC properties and technical details.

Design and implementation of a three-dimensional seven microphone acoustic intensity probe for measuring sound properties from various sources

Based on existing theoretical models of multi-dimensional cross-spectral methods for calculating sound pressure and particle velocities, this report has derived and/or extended models of intensity, energy densities, and specific acoustic impedance for seven microphone configurations. Array configuration, spacing, and overall implementation procedure is also outlined in this report. Experimental data has confirmed the validity of the analytical solution for different sound sources in both anechoic and reverberation room environment. Sound sources of different frequency bands [broadband (100 Hz–7 KHz), low (100 Hz–1 KHz), and high (1–7 KHz)] was used separately to compare accuracy and performance of the acoustic probe. Signal processing techniques and software implementation with potential errors and limitations of the system are explained. These would provide a framework for further refinement of instrumentation aspects of the acoustic probe. Potential applications and users of the probe are also described in this report.

Optically stimulated luminescence and its use in medical dosimetry

The optically stimulated luminescence (OSL) technique has already became a successful tool in personal radiation dosimetry, geological and archeological dating, and in radiation diagnostic imaging. This review briefly describes the history of OSL. Significant advances have been made recently in the theoretical study of OSL to explain the behavior of radiation sensitive materials with several types of dosimetry traps, recombination centers and competing deep traps. Progress in material and detector engineering has allowed new and promising developments regarding OSL applications in the medical field. Special attention is dedicated to Al 2O 3:C as a material of choice for many dosimetric applications; present technology can provide Al 2O 3:C fiber sensors with diameters as small as 300 μ m . A new RL/OSL fiberoptic system has a high potential for in vivo and in vitro dosimetry in both radiation therapy and diagnostic mammography. Different aspects of instrumentation, data processing algorithms, post-irradiation and real-time measurements are described.

06/01640 Design aspects of safety critical instrumentation of nuclear installations: Swaminathan, P. International Journal of Nuclear Energy Science and Technology, 2005, 1, (2–3), 254–263

06/01640 Design aspects of safety critical instrumentation of nuclear installations: Swaminathan, P. International Journal of Nuclear Energy Science and Technology, 2005, 1, (2–3), 254–263